Sweet Potato Cake | Saveur

Ingredients

• 26 tbsp. unsalted butter, plus more for pan
• 3 cups flour, plus more for pan
• 1 3⁄4 tsp. kosher salt
• 1 tbsp. baking powder
• 1 1⁄2 tsp. ground cinnamon
• 1 1⁄2 tsp. ground ginger
• 3⁄4 tsp. ground cardamom
• 1⁄2 tsp. baking soda
• 1⁄4 tsp. ground allspice
• 2 3⁄4 cups packed light brown sugar
• 4 eggs
• 2 cups mashed roasted sweet potatoes
• 3⁄4 cup sour cream
• 2 1⁄2 tsp. vanilla extract
• 8 oz. whole pecans
• 1 1⁄4 cups sugar
• 1⁄4 cup dark rum
• 2 egg whites
• 1 cup confectioners' sugar
• 1⁄4 cup milk